7–2 Cooling of a Hot Block by Forced Air at High Elevation
The local atmospheric pressure in Denver, Colorado (elevation 1610 m), is
83.4 kPa. Air at this pressure and 20°C flows with a velocity of 8 m/s over a
1.5 m 6 m flat plate whose temperature is 140°C (Fig. 7-13). Determine the
rate of heat transfer from the plate if the air flows parallel to the (a) 6-m-long
side and (b) the 1.5-m side.

Heat is added to a piston-cylinder device filled with 2 kg of air to raise its temperature 400 c from an initial temperature of t1 27 cand pressure of pi 1 mpa. the process is isobaric process. find a)-the final pressure p2 b)-the heat transfer to the air.

Ariver flows from north to south at 8 km/h. a boat is to cross this river from west to east at a speed of 20 km/h (speed of the boat with respect to the earth/ground). at what angle (in degrees) must the boat be pointed upstream such that it will proceed directly across the river (hint: find the speed of the boat with respect to water/river)? a 288 b. 21.8 c. 326 d. 30.2

Awall of 0.5m thickness is to be constructed from a material which has average thermal conductivity of 1.4 w/mk. the wall is to be insulated with a material having an average thermal conductivity of 0.35 w/mk so that heat loss per square meter shall not exceed 1450 w. assume inner wall surface temperature of 1200°c and outer surface temperature of the insulation to be 15°c. calculate the thickness of insulation required.